diff --git a/VersionNum b/VersionNum
index 7944206eebe00ff9a14975a3b5358cced625e828..210dc89308d09351f94c8afe94f34157968d8267 100644
--- a/VersionNum
+++ b/VersionNum
@@ -1,23 +1,23 @@
-/* (2.58)
+/* (2.59)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        2.58
+#define Module_MajorVersion_CMHG        2.59
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                29 Feb 2016
+#define Module_Date_CMHG                05 Apr 2016
 
-#define Module_MajorVersion             "2.58"
-#define Module_Version                  258
+#define Module_MajorVersion             "2.59"
+#define Module_Version                  259
 #define Module_MinorVersion             ""
-#define Module_Date                     "29 Feb 2016"
+#define Module_Date                     "05 Apr 2016"
 
-#define Module_ApplicationDate          "29-Feb-16"
+#define Module_ApplicationDate          "05-Apr-16"
 
 #define Module_ComponentName            "HdrSrc"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Programmer/HdrSrc"
 
-#define Module_FullVersion              "2.58"
-#define Module_HelpVersion              "2.58 (29 Feb 2016)"
-#define Module_LibraryVersionInfo       "2:58"
+#define Module_FullVersion              "2.59"
+#define Module_HelpVersion              "2.59 (05 Apr 2016)"
+#define Module_LibraryVersionInfo       "2:59"
diff --git a/hdr/NewErrors b/hdr/NewErrors
index 12c0bd035c11e1fe212f67ff2800d97693cf6228..d790648e6250e99cc42f84eba45e54dc7a625826 100644
--- a/hdr/NewErrors
+++ b/hdr/NewErrors
@@ -203,6 +203,7 @@ OldOpt  SETA    {OPT}
         AddError  NaffSWI,              "SWI not known", ErrorNumber_ModuleBadSWI
         AddError  NeedMod,              "Module %0 cannot start without module %1"
         AddError2 RMNot32bit,           "RMNot32bit:Module is not 32-bit compatible", ErrorNumber_BadRMHeaderField
+        AddError  BadErrPtr,            "BadErrPtr:SWI &%0 returned a bad error pointer"
 
 ; Variables errors
 
@@ -1550,5 +1551,7 @@ ErrorBase_BASIC                 #       &100    ; &0081FB00 Rob Sprowson
                          ^ &00820500
 ErrorBase_ATA                   #       &100    ; &00820500 Ben Avison
 ErrorBase_SPIDriver             #       &100    ; &00820600 John Ballance
+                         ^ &00820800
+ErrorBase_SerialUSB             #       &100    ; &00820800 Colin Granville
         OPT     OldOpt
         END
diff --git a/hdr/SWIs b/hdr/SWIs
index ab3d8255128b7f4f4aaf9e5c7ffecf726028e3fc..66a9b99ee96394005738e866add0ac5ebf4d6384 100644
--- a/hdr/SWIs
+++ b/hdr/SWIs
@@ -1748,6 +1748,16 @@ SATAFSSWI                       EQU     &00001663
 SATAFSSWI_Base                  EQU     &000598C0
 SATAFSSWI_Name                  SETS    "SATAFS"
 
+                                GBLS    CPUClockSWI_Name
+CPUClockSWI                     EQU     &00001666
+CPUClockSWI_Base                EQU     &00059980
+CPUClockSWI_Name                SETS    "CPUClock"
+
+                                GBLS    PL2303SWI_Name
+PL2303SWI                       EQU     &00001667
+PL2303SWI_Base                  EQU     &000599C0
+PL2303SWI_Name                  SETS    "PL2303"
+
 
         ; Application SWI Chunks